Frenic 5000VG7S Series, Instruction Manual

Page: 83 / 97

7-25
(18) RS485 communication error
NO
NO
NO
NO
YES
NO
NO
YES
Review
communication line.
YES
Review your checksum
and CRC programs.
Other errors on writing.
Refer to user's manual.
NO
NO
YES
YES
NO
Disable "No response error
detection time" setting.
Does inverter
communicate regularly in
specified time?
Format error
Comand error
Check your program.
RS485 communication error
Er5
Do you direct operation
command through RS485?
Is "No response error
detection time" (function code
H38) setting disabled?
Review device configuration to
decrease total wiring length to less
than specification.
If you use shielded line,
use commercial shielded
RS485 converter.
Separate power line from
communication line.
Specify response interval (H39)
according to specification
of used device.
Inverter noise is suspected.
Use "Mode selection on no response
error (H32)" to determine whether
you can continue operation.
Install terminating resistors.
Use shielded twisted pair cable.
Contact FUJI.
YES
YES
YES
NO
YES
Are terminating resistors
connected to both ends of
communication line?
Is total length of communication
line within specification?
Non-shielded: Max. 10m
Shielded: Max. 500m
Is response interval with respect
to send/receive switching time of
232C/485 converter meet
device to be used?
Is communication line tied with
power line?
YES
Is shielded twisted pair cable
used as communication line?
Does decreasing baud rate
(function code H34) down to
2,400bps eliminate alarm?
Check sum CRC error, Parity
framing, and Overrun error.
Is communication line
physically
disconnected?
Use maintenance
information of KEYPAD
panel to check RS485
error code.